We are mapping the chromosome of N. gonorrhoeae using a combination of procedures including linkage analysis via cotransformation and eventually marker frequency and density transfer analyses. We will also evaluate the 24.5M dal plasmid-mediated conjugation which transfers the genetic information for beta lactamase synthesis for its ability to promote chromosomal-marker transfer. The results of preliminary experiments although complicated by the existence of transformation between the type T4 donor and recipient cells, indicate that chromosomal mobilization may in fact occur. We will also attempt to cure strains of N. gonorrhoeae of resident prophages so that they can serve as indicators. In addition we will evaluate certain other strains which preliminary studies indicate may serve as indicators for plaque-forming units.